• Title/Summary/Keyword: 방향족 화학물질

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Separation and Identification of Polycyclic Aromatic Compounds in Pyrolysis Products of Cellulose and Lignin (셀룰로오스와 리그닌의 열분해 생성물중의 여러고리 방향족화합물의 분리와 동정)

  • Park, Nae-Joung;Lee, Milton L.
    • Journal of the Korean Chemical Society
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    • v.28 no.4
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    • pp.244-250
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    • 1984
  • Separation and identification of the polycyclic aromatic compounds (PAC) from pyrolysis products of cellulose and lignin were performed using a combination of acid-base solvent partitioning and silicic acid column chromatography with fused-silica capillary column gas chromatography/ mass spectrometry. Sixteen PAC were positively identifited by retention indices and mass spectra data. Both materials produced the same kinds of PAC. But lignin produced much more PAC than cellulose. Almost no highly carcinogenic heterocyclic PAC containing nitrogen and sulfur were produced.

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Syntheses and Arene Transport Studies of Water Soluble Aminomethylcalixarene (수용성 아미노메틸칼릭스아렌의 합성 및 방향족 물질의 통과실험 연구)

  • Kye Chung Nam;Dae Soon Kim
    • Journal of the Korean Chemical Society
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    • v.36 no.6
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    • pp.933-940
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    • 1992
  • Calix[6]arene react with formaldehyde and secondary amines to yields water soluble Mannich bases which can be converted to the corresponding quaternary salts. Treatment of the quaternary salts with a nucleophile such as cyano, ethoxy, and hydride yields p-substituted calix[6]arenes. Calix[8]arene too react with formaldehyde and diallyl amine to yield a water soluble Mannich base. The transport of neutral arenes through an aqueous phase along a concentration gradient mediated by those of water soluble calixarenes as molecular carrier was studied in a U-type cell. Naphthalene, anthracene, pyrene, and fluoranthene are tested as a neutral solid guest compounds for the transport experiment.

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Liquid Chromatography of Aromatic Sulfonic Acids by Tetramethylammonium Bromide (Tetramethylammonium Bromide를 이용한 방향족 술폰산들의 액체크로마토그래피)

  • Oh, Hae-Beom
    • Journal of the Korean Chemical Society
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    • v.37 no.9
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    • pp.793-799
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    • 1993
  • Ion-pair model was predominated over ion-interaction model in the retention mechanism of analytes when tetramethylammonium bromide (TMAB) was used as a counter-ion in the investigation of aromatic sulfonic acids on the reversed-phase liquid chromatography by $C_{18}$ column as a stationary phase. The capacity factors of analytes were influenced by the type and concentration of counter-ions, concentrations of methanol and co-anion, types and position of functional group, and the pH mobile phase. Components of analyte mixture could be separated under the optimum conditions by this method.

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The Effects of Sonic Waves on the Reduction of Aromatic Nitro Groups Using Iron, Hydrazine Hydrate and Activated Carbon (유기 초음파화학. 초음파가 히드라진, 철, 활성탄을 이용한 방향족 니트로기의 환원반응에 미치는 영향)

  • Dae Hyun Shin;Byung Hee Han;Sung Yun Cho
    • Journal of the Korean Chemical Society
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    • v.30 no.1
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    • pp.105-108
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    • 1986
  • Ultrasound(50KHz) accelerated the reduction reaction of aromatic nitro group to aromatic amino group in high yield with mild condition using iron, hydrazine hydrate and activated carbon under room temperature and atmospheric pressure. The activated carbon has been used as a mixing material to highly active metals. However, aromatic nitro group does not reduce at all only with iron-hydrazine witliout adding activated carbon even under ultrasonic irradiation. We also discovered that the conversion yield from nitro group to amino group is directly proportional to the amount of activated carbon.

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Treatment of hazardous chemicals by Nanoscale Iron powder (나노크기 철 분말을 이용한 난분해성 유해화합물질의 처리)

  • 최승희;장윤영;황경엽;김지형
    • Journal of Korea Soil Environment Society
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    • v.4 no.3
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    • pp.85-93
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    • 1999
  • The destruction of hazardous chemicals such as chlorinated organic compounds(COCs) and nitroaromatic compounds(NACs) by zero-valent iron powder is one of the latest innovative technologies. In this paper. the rapid dechlorination of chlorinated compounds as well as transformation of nitro functional group to amine functional group in the nitroaromatic compounds using synthesized zero-valent iron powder with nanoscale were studied in anaerobic batch system. Nanoscale iron, characterized by high surface area to mass ratios(31.4$\textrm{m}^2$/g) and high reactivity, could quickly reacts with compounds such as TCE, chloroform, nitrobenzene, nitrotoluene, dinitrobenzene and dinitrotoluene, at concentration of 10mg/L in aqueous solution at room temperature and pressure. In this study, the TCE was dechlorinated to ethane and chloroform to methane and nitro groups in NACs were transformed to amino groups in less than 30min. These results indicated that this chemical method using nanoscale iron powder has the high potential for the remediation of soils and groundwater contaminated with hazardous toxic chemicals including chlorinated organic compounds and nitro aromatic compounds.

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Isolation of Pseudomonas putida Z104 and Degra-dation Characteristics of Benzoate and Catechol (Benzoate와 Catechol을 분해하는 Pseudomonas putida Z104의 분리 및 분해특성)

  • 김기필;김준호;김민옥;박정아;정원화;김치경
    • Korean Journal of Environmental Biology
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    • v.18 no.3
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    • pp.307-313
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    • 2000
  • Aromatic hydrocarbons are known to be recalcitrant, so that they have been concerned as pollutant chemicals. Microorganisms play a major role in the breakdown and mineralization of these compounds. However, the kinetics of the biodegradation process may be much slower than desired from environmental consideration. The biodegradation of aromatic hydrocarbons is conducted by oxidation to produce catechol as a common intermediate which is metabolized for carbon and energy sources. In this study, a bacterial isolate capable of degrading several aromatic hydrocarbons was isolated from the contaminated wastewater of Yeocheon industrial complex. On the basis of biochemical characteristics and major cellular fatty acids, the isolate was identified as Pseudomonas putida Z104. The strain Z104 can utilize benzoate and catechol as the sole carbon and energy sources via a serial degradative pathway. The strain degraded actively 0.5 mM catechol in MM2 medium at pH 7.0 and 3$0^{\circ}C$.

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Biodegradation of Recalcitrant Chlorinated Aromatic Compounds via Microbial Dechlorination (미생물의 탈염소화 작용에 의한 난분해성 염화방향족 오염물질의 분해)

  • 채종찬;김치경
    • Korean Journal of Environmental Biology
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    • v.17 no.2
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    • pp.129-138
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    • 1999
  • Chlorinated aromatic compounds are one of the largest groups of environmental pollutants as a result of world-wide distribution by using them as herbicides, insecticides, fungicides, solvents, hydraulic and heat transfer fluids, plasticizers, and intermediates for chemical synthesis. Because of their toxicity, persistence, and bioaccumulation, the compounds contaminated ubiquitously in the biosphere has attracted public concerns in terms of serious influences to wild lives and a human being, such as carcinogenicity, mutagenicity, and disturbance in endocrine systems. The biological recalcitrance of the compounds is caused by the number, type, and position of the chlorine substituents as well as by their aromatic structures. In general, the carbon-halogen bonds increase the recalcitrance by increasing electronegativity of the substituent, so that the dechlorination of the compounds is focused as an important mechanism for biodegradation of chlorinated aromatics, along with the cleavage of aromatic rings. The removal of the chlorine substituents has been known as a key step for degradation of chlorinated aromatic compounds under aerobic condition. This can occur as an initial step via oxygenolytic, reductive, and hydrolytic mechanisms. The studies on the biochemistry and genetics about microbial dechlorination give us the potential informations for microbial degradation of xenobiotics contaminated in natural microcosms. Such investigations might provide biotechnological approaches to solve the environmental contamination, such as designing effective bioremediation systems using genetically engineered microorganisms.

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Separation of Aromatics in Light Cycle Oil by Solvent Extraction - Re-extraction of Aromatics in Extract Phase - (용매 추출법에 의한 분해경유중의 방향족 분리 -추출상중의 방향족의 역수출-)

  • Kim, Su Jin;Kim, Duk-Hyun
    • Applied Chemistry for Engineering
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    • v.8 no.6
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    • pp.967-972
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    • 1997
  • Recovery of aromatics in extract phase which was obtained by batch equilibrium extraction between light cycle oil(LCO) and dimethylsulfoxide(DMSO) solution as solvent was investigated by re-extraction. To select the most suitable re-extraction solvent for recovery of aromatics in extract phase, distribution equilibrium was measured between extract phase and solvents. The solvents used were benzene(B), toluene(T), m-Xylene(mX), n-hexane(Hx) and n-hexane(Hx) and n-Octane(Ot). From the distribution coefficients and yields of aromatics, Hx seemed to be the most suitable. Furthermore, effects of operation parameters for re-extraction of aromatics in the extract phase were studied by batch equilibrium re-extracion with Hx as solvent. Yields of aromatics were found to increase with increasing solvent/feed (extract phase) mass ratio(S/F), while distribution coefficients of aromatics were fixed irrespective of S/F used. Operating temperature did not affect distribution coefficients and yields of aromatics. Distibution coefficients and yields of naphthalene group(carbon numer : 10~12) increased with increasing cabon number. Mass transfer rates of aromatics were also measured with a batch stirred vessel.

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